Mixed fault analysis of 3-phase cage induction motor based on winding function theory

This paper studies on the fault analysis of 3-phase cage induction motor with the mixed fault of the static eccentricity and the broken rotor bars at steady state. A mathematical fault model is presented by the coupled magnetic circuit approach. The calculation of winding inductances is derived by means of a winding function theory. The stator current and the torque are obtained by means of the coupled magnetic circuit method and Park's transformation. The characteristics of single fault and mixed fault are analyzed. From the simulation results it is shown that there is its own peculiar frequency component obtained by the spectrum analysis of the stator current in the case of a single fault. But in the case of mixed fault, there is a mutual effect between two faults. From the comparison with FEM results, it is shown that the proposed approach can be simulated to diagnose faults in 3-phase cage induction motor.